A Phase 1/2 Study to Evaluate the Safety and Activity of Nivolumab in Combination With Vorolanib, a Vascular Endothelial Growth Factor Tyrosine Kinase Inhibitor, in Patients With Refractory Thoracic Tumors

Introduction

Targeting the tumor microenvironment may enhance response to immunotherapy (immune checkpoint inhibitors) and improve outcomes for patients. This study tested the safety and efficacy of vorolanib, a novel tyrosine kinase inhibitor of vascular endothelial growth factor, platelet-derived growth factor, and c-KIT, in combination with programmed cell death protein 1 blockade using nivolumab for refractory thoracic malignancies.

Methods

This single-arm multicenter study enrolled patients with extensive-stage SCLC, thymic carcinoma, and NSCLC, either naive or had progressed on previous chemotherapy or immune checkpoint inhibitors (either primary or acquired resistance). The primary objective of phase 1 was to determine the maximum tolerated dose, and the primary end point for each dose-expansion cohort was the objective response rate.

Results

A total of 88 patients were enrolled in phase 1 (n = 11) and dose expansion (n = 77) cohorts. Transaminitis was dose-limiting and expansion proceeded with oral vorolanib 200 mg daily combined with intravenous nivolumab 240 mg every 2 weeks. The objective response rate per cohort were as follows: NSCLC naive 33% (five of 15, 95% confidence interval [CI]: 13%-60%), NSCLC primary refractory 5.9% (one of 17, 95% CI: 0%-17.6%), NSCLC acquired resistance 11.1% (two of 18, 95% CI: 0%-27.8%); SCLC 0% (zero of 18), and thymic carcinoma 11% (one of nine, 95% CI: 0%-33%). Disease control rate ranged from 11.1% in SCLC (two of 18, 0%-27.8%) to 66.7 % in thymic carcinoma (six of nine, 95% CI: 33.3%-100%). The most common adverse events were fatigue (32%), aspartate transaminase (27%) and alanine transaminase elevation (25%), and diarrhea (19%). Transaminitis was more common in patients with thymic carcinoma than other tumors.

Conclusions

Vorolanib plus nivolumab had a manageable safety profile and may have clinical benefits in various thoracic malignancies. The disease control rate in thymic malignancies warrants further assessment.

Disparities in outcomes between Black and White patients in North America with thoracic malignancies and COVID-19 infection (TERAVOLT)

BACKGROUND

Patients with thoracic malignancies who develop COVID-19 infection have a higher hospitalization rate compared to the general population and to those with other cancer types, but how this outcome differs by race and ethnicity is relatively understudied.

METHODS

The TERAVOLT database is an international, multi-center repository of cross-sectional and longitudinal data studying the impact of COVID-19 on individuals with thoracic malignancies. Patients from North America with thoracic malignancies and confirmed COVID-19 infection were included for this analysis of racial and ethnic disparities. Patients with missing race data or races and ethnicities with fewer than 50 patients were excluded from analysis. Multivariable analyses for endpoints of hospitalization and death were performed on these 471 patients.

RESULTS

Of the 471 patients, 73% were White and 27% were Black. The majority (90%) were non-Hispanic ethnicity, 5% were Hispanic, and 4% were missing ethnicity data. Black patients were more likely to have an Eastern Cooperative Oncology Group (ECOG) Performance Status ≥ 2 (p-value = 0.04). On multivariable analysis, Black patients were more likely than White patients to require hospitalization (Odds Ratio (OR): 1.69, 95% CI: 1.01-2.83, p-value = 0.044). These differences remained across different waves of the pandemic. However, no statistically significant difference in mortality was found between Black and White patients (OR 1.29, 95% CI: 0.69-2.40, p-value = 0.408).

CONCLUSIONS

Black patients with thoracic malignancies who acquire COVID-19 infection are at a significantly higher risk of hospitalization compared to White patients, but there is no significant difference in mortality. The underlying drivers of racial disparity among patients with thoracic malignancies and COVID-19 infection require ongoing investigation.

Identification and Characterization of Avoidable Hospital Admissions in Patients With Lung Cancer

BACKGROUND

More than 50% of patients with lung cancer are admitted to the hospital while receiving treatment, which is a burden to patients and the healthcare system. This study characterizes the risk factors and outcomes of patients with lung cancer who were admitted to the hospital.

METHODS

A multidisciplinary oncology care team conducted a retrospective medical record review of patients with lung cancer admitted in 2018. Demographics, disease and admission characteristics, and end-of-life care utilization were recorded. Following a multidisciplinary consensus review process, admissions were determined to be either "avoidable" or "unavoidable." Generalized estimating equation logistic regression models assessed risks and outcomes associated with avoidable admissions.

RESULTS

In all, 319 admissions for 188 patients with a median age of 66 years (IQR, 59-74 years) were included. Cancer-related symptoms accounted for 65% of hospitalizations. Common causes of unavoidable hospitalizations were unexpected disease progression causing symptoms, chronic obstructive pulmonary disease exacerbation, and infection. Of the 47 hospitalizations identified as avoidable (15%), the median overall survival was 1.6 months compared with 9.7 months (hazard ratio, 2.07; 95% CI, 1.34-3.19; P<.001) for unavoidable hospitalizations. Significant reasons for avoidable admissions included cancer-related pain (P=.02), hypervolemia (P=.03), patient desire to initiate hospice services (P=.01), and errors in medication reconciliation or distribution (P<.001). Errors in medication management caused 26% of the avoidable hospitalizations. Of admissions in patients receiving immunotherapy (n=102) or targeted therapy (n=44), 9% were due to adverse effects of treatment. Patients receiving immunotherapy and targeted therapy were at similar risk of avoidable hospitalizations compared with patients not receiving treatment (P=.3 and P=.1, respectively).

CONCLUSIONS

We found that 15% of hospitalizations among patients with lung cancer were potentially avoidable. Uncontrolled symptoms, delayed implementation of end-of-life care, and errors in medication reconciliation were associated with avoidable inpatient admissions. Symptom management tools, palliative care integration, and medication reconciliations may mitigate hospitalization risk.

Receipt of Bilateral Mastectomy Among Women With Hereditary Breast Cancer

This case series study examines differences in surgical treatment among adult females with invasive breast cancer who have pathogenic or likely pathogenic variants in genes with high vs moderate breast cancer penetrance.

Characterization of avoidable hospital admissions in patients with lung cancer in the immunotherapy and targeted therapy era

e21133

Background: Hospitalization is the second largest contributor of cancer care spending, and over 50% of lung cancer patients are admitted to the hospital while receiving treatment. Patients who avoid hospital admission have reduced health care costs with a higher quality of life. This is the first study that characterizes the risk factors and outcomes for avoidable hospital admissions of lung cancer patients. It is the first to examine the extent to which hospitalizations from immunotherapy and targeted therapy could be avoided. Methods: A retrospective chart review of lung cancer patients admitted January 2018 through December 2018 was conducted. Demographics, disease and treatment history, admission characteristics, outcomes, and end-of-life care utilization were recorded. Following a multidisciplinary consensus review, hospitalizations were determined “avoidable” or “unavoidable.” Generalized estimating equation logistic regression models analyzed risks and outcomes associated with avoidable admissions. Kaplan-Meier estimators examined the median overall survival (mOS) between patients with and without avoidable admissions. Results: We evaluated 319 admissions from 188 patients with a median age of 66 and 16%/84% SCLC/NSCLC. Cancer-related symptoms accounted for 66% of hospitalizations; pneumonia and other infections comprised 34%, and 32% were due to cancer-related pain, vomiting, or failure to thrive (FTT). Common causes of unavoidable hospitalizations were unexpected disease progression causing symptoms, COPD exacerbation, and infection. Of the 47 hospitalizations identified as avoidable (15%), the mOS was 1.6 months; the mOS of unavoidable hospitalizations was 9.7 months (HR 2.07; 95% CI 1.34-3.19; p < 0.001). Significant reasons for avoidable admissions included cancer-related pain (p = 0.021), hypervolemia (p = 0.033), patient desire to initiate hospice services (p = 0.011), and errors in medication reconciliation or distribution (p < 0.001). Errors in medication management caused 26% of the avoidable hospitalizations. Of admissions in patients on immunotherapy (n = 102) or targeted therapy (n = 44), 9% were due to adverse effects of treatment. Patients on immunotherapy and targeted therapy were not more likely to have avoidable hospitalizations compared to patients not on the treatments (p = 0.323 and 0.133, respectively). Patients with avoidable admissions were 3.02 times more likely to enroll in hospice within 30 days of hospitalization compared to unavoidable admissions (95% CI 1.54-5.92; p = 0.001). Conclusions: Patients on immunotherapy or targeted therapy were only rarely admitted due to side effects of treatment. Hospitalizations may be avoided with more aggressive outpatient symptom management, earlier hospice discussion with at-risk patients, and outpatient pharmacist review of medications following hospital discharge.

COVID-19 in patients with cancer: first report of the ESMO international, registry-based, cohort study (ESMO-CoCARE)

BACKGROUND

ESMO COVID-19 and CAncer REgistry (ESMO-CoCARE) is an international collaborative registry-based, cohort study gathering real-world data from Europe, Asia/Oceania and Africa on the natural history, management and outcomes of patients with cancer infected with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2).

PATIENTS AND METHODS

ESMO-CoCARE captures information on patients with solid/haematological malignancies, diagnosed with coronavirus disease 2019 (COVID-19). Data collected since June 2020 include demographics, comorbidities, laboratory measurements, cancer characteristics, COVID-19 clinical features, management and outcome. Parameters influencing COVID-19 severity/recovery were investigated as well as factors associated with overall survival (OS) upon SARS-CoV-2 infection.

RESULTS

This analysis includes 1626 patients from 20 countries (87% from 24 European, 7% from 5 North African, 6% from 8 Asian/Oceanian centres), with COVID-19 diagnosis from January 2020 to May 2021. Median age was 64 years, with 52% of female, 57% of cancer stage III/IV and 65% receiving active cancer treatment. Nearly 64% patients required hospitalization due to COVID-19 diagnosis, with 11% receiving intensive care. In multivariable analysis, male sex, older age, Eastern Cooperative Oncology Group (ECOG) performance status ≥2, body mass index (BMI) <25 kg/m2, presence of comorbidities, symptomatic disease, as well as haematological malignancies, active/progressive cancer, neutrophil-to-lymphocyte ratio (NLR) ≥6 and OnCovid Inflammatory Score ≤40 were associated with COVID-19 severity (i.e. severe/moderate disease requiring hospitalization). About 98% of patients with mild COVID-19 recovered, as opposed to 71% with severe/moderate disease. Advanced cancer stage was an additional adverse prognostic factor for recovery. At data cut-off, and with median follow-up of 3 months, the COVID-19-related death rate was 24.5% (297/1212), with 380 deaths recorded in total. Almost all factors associated with COVID-19 severity, except for BMI and NLR, were also predictive of inferior OS, along with smoking and non-Asian ethnicity.

CONCLUSIONS

Selected patient and cancer characteristics related to sex, ethnicity, poor fitness, comorbidities, inflammation and active malignancy predict for severe/moderate disease and adverse outcomes from COVID-19 in patients with cancer.

COVID-19 Outcomes, Patient Vaccination Status, and Cancer-Related Delays during the Omicron Wave: A Brief Report from the TERAVOLT Analysis

Introduction

The Thoracic Centers International coronavirus disease 2019 (COVID-19) Collaboration (TERAVOLT) registry found approximately 30% mortality in patients with thoracic malignancies during the initial COVID-19 surges. Data from South Africa suggested a decrease in severity and mortality with the Omicron wave. Our objective was to assess mortality of patients with thoracic malignancies with the Omicron-predominant wave and evaluate efficacy of vaccination.

Methods

A prospective, multicenter observational study was conducted. A total of 28 institutions contributed data from January 14, 2022, to February 4, 2022. Inclusion criteria were any thoracic cancer and a COVID-19 diagnosis on or after November 1, 2021. End points included mortality, hospitalization, symptomatic COVID-19 infection, asymptomatic COVID-19 infection, and delay in cancer therapy. Analysis was done through contingency tables and a multivariable logistic model.

Results

We enrolled a total of 346 patients. Median age was 65 years, 52.3% were female, 74.2% were current or former smokers, 86% had NSCLC, 72% had stage IV at time of COVID-19 diagnosis, and 66% were receiving cancer therapy. Variant was unknown for 70%; for those known, Omicron represented 82%. Overall mortality was 3.2%. Using multivariate analysis, COVID-19 vaccination with booster compared with no vaccination had a protective effect on hospitalization or death (OR = 0.30, confidence interval: 0.15–0.57, p = 0.0003), whereas vaccination without booster did not (OR = 0.64, confidence interval: 0.33–1.24, p = 0.1864). Cancer care was delayed in 56.4% of the patients.

Conclusions

TERAVOLT found reduced patient mortality with the most recent COVID-19 surge. COVID-19 vaccination with booster improved outcomes of hospitalization or death. Delays in cancer therapy remain an issue, which has the potential to worsen cancer-related mortality.

Palliative Care Exposure Relative to Predicted Risk of Six-Month Mortality in Hospitalized Adults

CONTEXT

The optimal strategy for implementing mortality-predicting algorithms to facilitate clinical care, prognostic discussions, and palliative care interventions remains unknown.

OBJECTIVES

To develop and validate a real-time predictive model for 180 day mortality using routinely available clinical and laboratory admission data and determine if palliative care exposure varies with predicted mortality risk.

METHODS

Adult admissions between October 1, 2013 and October.1, 2017 were included for the model derivation. A separate cohort was collected between January 1, 2018 and July 31, 2020 for validation. Patients were followed for 180 days from discharge, and logistic regression with selected variables was used to estimate patients' risk for mortality.

RESULTS

In the model derivation cohort, 7963 events of 180 day mortality (4.5% event rate) were observed. Median age was 53.0 (IQR 24.0-66.0) with 92,734 females (52.5%). Variables with strongest association with 180 day mortality included: Braden Score (OR 0.83; 95% CI 0.82-0.84); admission Do Not Resuscitate orders (OR 2.61; 95% CI 2.43-2.79); admission service and admission status. The model yielded excellent discriminatory ability in both the derivation (c-statistic 0.873; 95% CI 0.870-0.877; Brier score 0.04) and validation cohorts (c-statistic 0.844; 95% CI 0.840-0.847; Brier score 0.072). Inpatient palliative care consultations increased from 3% of minimal-risk encounters to 41% of high-risk encounters (P < 0.01).

CONCLUSION

We developed and temporally validated a predictive mortality model for adults from a large retrospective cohort, which helps quantify the potential need for palliative care referrals based on risk strata. Machine learning algorithms for mortality require clinical interpretation, and additional studies are needed to design patient-centered and risk-specific interventions.

First-in-human trial exploring safety, antitumor activity, and pharmacokinetics of Sym013, a recombinant pan-HER antibody mixture, in advanced epithelial malignancies

PURPOSE

 Sym013 contains six humanized monoclonal antibodies that bind to non-overlapping epitopes on three human epidermal growth factor receptors (HER1-3). Preclinical studies suggested Sym013 strongly suppresses growth of multiple epithelial tumors. This is a first-in-human study exploring safety and efficacy of Sym013 in patients with advanced epithelial malignancies.

METHODS

 Dose escalation used single-patient cohorts until the stopping rule was met, followed by 3 + 3 design. Dose levels planned were: 1, 2, 4, 6, 9, 12, 15, and 18 mg/kg. Treatment cycles were 28 days with imaging every eight weeks. Serum samples were collected at multiple time points for assessment of pharmacokinetics and development of anti-drug antibodies.

RESULTS

 Thirty-two patients were enrolled with multiple solid tumors, most common being colorectal cancer (CRC; 10/32, 31%). Due to mucositis, rash, and diarrhea at 4 mg/kg once-weekly, dosing was changed to biweekly (Q2W). Mandatory prophylaxis was added due to Grade 3 infusion-related reaction and oral mucositis at 9 mg/kg Q2W. The 15 mg/kg Q2W cohort was enrolling when the study was terminated for business reasons. Most common adverse events were skin (81%) and gastrointestinal (75%) disorders, including dermatitis/rash, stomatitis, and diarrhea. One patient with CRC achieved a partial response; 12 patients with varied malignancies had stable disease.

CONCLUSION

 During the conduct of the study, management of frequent infusion-related reactions, skin toxicities, and mucosal disorders, which are indicative of HER inhibition, necessitated multiple protocol amendments. The investigators, in concert with the Sponsor, agreed that achieving a tolerated regimen with acceptable target saturation was unlikely.

TRIAL REGISTRY

www.clinicaltrials.gov ; NCT02906670 (September 20, 2016).

COVID-19 and Cancer: A Review of the Registry-Based Pandemic Response

Importance

The COVID-19 pandemic has had consequences for patients with cancer worldwide and has been associated with delays in diagnosis, interruption of treatment and follow-up care, and increases in overall infection rates and premature mortality.

Observations

Despite the challenges experienced during the pandemic, the global oncology community has responded with an unprecedented level of investigation, collaboration, and technological innovation through the rapid development of COVID-19 registries that have allowed an increased understanding of the natural history, risk factors, and outcomes of patients with cancer who are diagnosed with COVID-19. This review describes 14 major registries comprising more than 28 500 patients with cancer and COVID-19; these ongoing registry efforts have provided an improved understanding of the impact and outcomes of COVID-19 among patients with cancer.

Conclusions and Relevance

An initiative is needed to promote active collaboration between different registries to improve the quality and consistency of information. Well-designed prospective and randomized clinical trials are needed to collect high-level evidence to guide long-term epidemiologic, behavioral, and clinical decision-making for this and future pandemics.

Enhancing Cancer care of rural dwellers through telehealth and engagement (ENCORE): protocol to evaluate effectiveness of a multi-level telehealth-based intervention to improve rural cancer care delivery

BACKGROUND

Despite lower cancer incidence rates, cancer mortality is higher among rural compared to urban dwellers. Patient, provider, and institutional level factors contribute to these disparities. The overarching objective of this study is to leverage the multidisciplinary, multispecialty oncology team from an academic cancer center in order to provide comprehensive cancer care at both the patient and provider levels in rural healthcare centers. Our specific aims are to: 1) evaluate the clinical effectiveness of a multi-level telehealth-based intervention consisting of provider access to molecular tumor board expertise along with patient access to a supportive care intervention to improve cancer care delivery; and 2) identify the facilitators and barriers to future larger scale dissemination and implementation of the multi-level intervention.

METHODS

Coordinated by a National Cancer Institute-designated comprehensive cancer center, this study will include providers and patients across several clinics in two large healthcare systems serving rural communities. Using a telehealth-based molecular tumor board, sequencing results are reviewed, predictive and prognostic markers are discussed, and treatment plans are formulated between expert oncologists and rural providers. Simultaneously, the rural patients will be randomized to receive an evidence-based 6-week self-management supportive care program, Cancer Thriving and Surviving, versus an education attention control. Primary outcomes will be provider uptake of the molecular tumor board recommendation and patient treatment adherence. A mixed methods approach guided by the Consolidated Framework for Implementation Research that combines qualitative key informant interviews and quantitative surveys will be collected from both the patient and provider in order to identify facilitators and barriers to implementing the multi-level intervention.

DISCUSSION

The proposed study will leverage information technology-enabled, team-based care delivery models in order to deliver comprehensive, coordinated, and high-quality cancer care to rural and/or underserved populations. Simultaneous attention to institutional, provider, and patient level barriers to quality care will afford the opportunity for us to broadly share oncology expertise and develop dissemination and implementation strategies that will enhance the cancer care delivered to patients residing within underserved rural communities.

TRIAL REGISTRATION

Clinicaltrials.gov , NCT04758338 . Registered 17 February 2021 - Retrospectively registered, http://www.clinicaltrials.gov/.

IMProving care After inherited Cancer Testing (IMPACT) study: protocol of a randomized trial evaluating the efficacy of two interventions designed to improve cancer risk management and family communication of genetic test results

BACKGROUND

Implementing genetic testing for inherited cancer predisposition into routine clinical care offers a tremendous opportunity for cancer prevention and early detection. However, genetic testing itself does not improve outcomes; rather, outcomes depend on implemented follow-up care. The IMPACT study is a hybrid type I randomized effectiveness-implementation trial to simultaneously evaluate the effectiveness of two interventions for individuals with inherited cancer predisposition focused on: 1) increasing family communication (FC) of genetic test results; and 2) improving engagement with guideline-based cancer risk management (CRM).

METHODS

This prospective study will recruit a racially, geographically, and socioeconomically diverse population of individuals with a documented pathogenic/likely pathogenic (P/LP) variant in an inherited cancer gene. Eligible participants will be asked to complete an initial trial survey and randomly assigned to one of three arms: A) GeneSHARE, a website designed to increase FC of genetic test results; B) My Gene Counsel's Living Lab Report, a digital tool designed to improve understanding of genetic test results and next steps, including CRM guidelines; or C) a control arm in which participants continue receiving standard care. Follow-up surveys will be conducted at 1, 3, and 12 months following randomization. These surveys include single-item measures, scales, and indices related to: 1) FC and CRM behaviors and behavioral factors following the COM-B theoretical framework (i.e., capability, opportunity, and motivation); 2) implementation outcomes (i.e., acceptability, appropriateness, exposure, and reach); and 3) other contextual factors (i.e., sociodemographic and clinical factors, and uncertainty, distress, and positive aspects of genetic test results). The primary outcomes are an increase in FC of genetic test results (Arm A) and improved engagement with guideline-based CRM without overtreatment or undertreatment (Arm B) by the 12-month follow-up survey.

DISCUSSION

Our interventions are designed to shift the paradigm by which individuals with P/LP variants in inherited cancer genes are provided with information to enhance FC of genetic test results and engagement with guideline-based CRM. The information gathered through evaluating the effectiveness and implementation of these real-world approaches is needed to modify and scale up adaptive, stepped interventions that have the potential to maximize FC and CRM.

TRIAL REGISTRATION

This study is registered at Clinicaltrials.gov (NCT04763915, date registered: February 21, 2021).

PROTOCOL VERSION

September 17th, 2021 Amendment Number 04.

Ensartinib vs Crizotinib for Patients With Anaplastic Lymphoma Kinase-Positive Non-Small Cell Lung Cancer: A Randomized Clinical Trial

Question

Is ensartinib superior to crizotinib for patients with advanced anaplastic lymphoma kinase (ALK)–positive non–small cell lung cancer (NSCLC) who have not been treated previously with an ALK inhibitor?

Findings

This randomized clinical phase 3 trial including 290 patients met the primary end point; the median progression-free survival was statistically significantly longer with ensartinib than with crizotinib (25.8 vs 12.7 months), and the confirmed intracranial response rate was 64% with ensartinib vs 21% with crizotinib for patients with brain metastases at baseline. Ensartinib had a favorable safety profile.

Meaning

Ensartinib represents a new first-line treatment option for patients with ALK-positive NSCLC.

Importance

Ensartinib, an oral tyrosine kinase inhibitor of anaplastic lymphoma kinase (ALK), has shown systemic and central nervous system efficacy for patients with ALK-positive non–small cell lung cancer (NSCLC).

Objective

To compare ensartinib with crizotinib among patients with advanced ALK-positive NSCLC who had not received prior treatment with an ALK inhibitor.

Design, Setting, and Participants

This open-label, multicenter, randomized, phase 3 trial conducted in 120 centers in 21 countries enrolled 290 patients between July 25, 2016, and November 12, 2018. Eligible patients were 18 years of age or older and had advanced, recurrent, or metastatic ALK-positive NSCLC.

Interventions

Patients were randomized (1:1) to ensartinib, 225 mg once daily, or crizotinib, 250 mg twice daily.

Main Outcomes and Measures

The primary end point was blinded independent review committee–assessed progression-free survival (PFS). Secondary end points included systemic and intracranial response, time to central nervous system progression, and overall survival. Efficacy was evaluated in the intent-to-treat (ITT) population as well as a prespecified modified ITT (mITT) population consisting of patients with central laboratory–confirmed ALK-positive NSCLC.

Results

A total of 290 patients (149 men [51.4%]; median age, 54 years [range, 25-90 years]) were randomized. In the ITT population, the median PFS was significantly longer with ensartinib than with crizotinib (25.8 [range, 0.03-44.0 months] vs 12.7 months [range, 0.03-38.6 months]; hazard ratio, 0.51 [95% CI, 0.35-0.72]; log-rank P < .001), with a median follow-up of 23.8 months (range, 0-44 months) for the ensartinib group and 20.2 months (range, 0-38 months) for the crizotinib group. In the mITT population, the median PFS in the ensartinib group was not reached, and the median PFS in the crizotinib group was 12.7 months (95% CI, 8.9-16.6 months; hazard ratio, 0.45; 95% CI, 0.30-0.66; log-rank P < .001). The intracranial response rate confirmed by a blinded independent review committee was 63.6% (7 of 11) with ensartinib vs 21.1% (4 of 19) with crizotinib for patients with target brain metastases at baseline. Progression-free survival for patients without brain metastases was not reached with ensartinib vs 16.6 months with crizotinib as a result of a lower central nervous system progression rate (at 12 months: 4.2% with ensartinib vs 23.9% with crizotinib; cause-specific hazard ratio, 0.32; 95% CI, 0.16-0.63; P = .001). Frequencies of treatment-related serious adverse events (ensartinib: 11 [7.7%] vs crizotinib: 9 [6.1%]), dose reductions (ensartinib: 34 of 143 [23.8%] vs crizotinib: 29 of 146 [19.9%]), or drug discontinuations (ensartinib: 13 of 143 [9.1%] vs crizotinib: 10 of 146 [6.8%]) were similar, without any new safety signals.

Conclusions and Relevance

In this randomized clinical trial, ensartinib showed superior efficacy to crizotinib in both systemic and intracranial disease. Ensartinib represents a new first-line option for patients with ALK-positive NSCLC.

Trial Registration

ClinicalTrials.gov Identifier: NCT02767804

A randomized phase III study of immune checkpoint inhibition with chemotherapy in treatment-naive metastatic anal cancer patients: A trial of the ECOG-ACRIN cancer research group (EA2176)

TPS3614

Background: Anal cancer is growing in annual incidence globally and human papillomavirus (HPV) remains the predominant risk factor underlying its development. Due to its relative rarity, clinical trials in anal cancer have historically been difficult to conduct and treatment options for metastatic disease remain limited. Carboplatin/paclitaxel (CP) was compared to cisplatin/5-fluorouracil (historical standard of care) in a recent randomized phase II clinical trial (InterAACT; EA2133) in treatment-naïve metastatic anal cancer, finding that response rates were equivocal, but that overall survival (OS) was significantly longer in the CP arm (20 months vs 12.3 months, p = 0.014). Additionally, reduced grade 3/4 toxicities were seen in the CP arm. NCI9673, a single-arm phase II study, established safety and efficacy of nivolumab in previously-treated metastatic anal cancer. Progression-free survival (PFS) was 4.1 months (95% CI 3.0-7.9) and OS was 11.5 months (95% CI 7.1-not estimable). Multiple randomized trials in lung cancer have demonstrated efficacy of platinum-based chemotherapy combined with checkpoint inhibitors. Together these studies form the rationale behind combining CP and nivolumab in treatment-naïve metastatic anal cancer. Methods: EA2176 (NCT04444921) is the first NCTN phase III randomized clinical trial in treatment-naïve metastatic anal cancer. Stratification factors include HIV status and history of chemoradiation for curative intent. Patients will be randomized to carboplatin (AUC = 5, Day 1) plus paclitaxel (80mg/m2, Days 1, 8, 15) +/- nivolumab 240mg IV (Cycle 1 = Days 1, 15; Cycle ≥2 = Day 1, 480mg) q 28-days until disease progression or treatment intolerance. CP will be given for up to 6 cycles, while nivolumab will be continued as maintenance for up to 2 years. The primary endpoint is PFS. Secondary objectives include OS, response rate, and toxicity. Goal enrollment is 205 patients and the study continues accrual. This sample size will provide 80% power at a two-sided α of 0.05 to detect a 4.8-month improvement in PFS assuming 8 months in the control arm. Novel correlative studies include sequential quantitative tumor-derived cell-free HPV ctDNA levels (serotypes 16 and 18; Sysmex-Inostics SafeSEQ NGS assay). Correlative funding provided in part by the Farrah Fawcett Foundation and Sysmex Inostics, Inc. Clinical trial information: NCT04444921.

Phase I/II study of nivolumab plus vorolanib in patients with thoracic malignancies: Interim efficacy of the SCLC and primary refractory NSCLC cohorts, and safety data across all cohorts

2578

Background: Combination strategies to improve the efficacy of single agent immune checkpoint inhibitors (ICIs) are increasingly being explored, with one strategy being the addition of vascular endothelial growth factor (VEGF) inhibition. Having shown promise in the treatment of hepatocellular carcinoma and renal cell carcinoma, NCT03583086 is a multi-institutional, phase I/II study of combination vorolanib and nivolumab in both naïve and refractory thoracic tumors that progressed on at least one prior line of platinum-based chemotherapy. Though structurally similar to the tyrosine kinase inhibitor, sunitinib, vorolanib was designed to have a more favorable safety profile with comparable efficacy. Here we present safety data across all cohorts and interim efficacy analyses of the SCLC and NSCLC with primary resistance to ICI-based therapy cohorts, both of which have now completed enrolment. Methods: The maximum tolerated dose determined in phase I was vorolanib 200mg daily and nivolumab 240mg q2 weeks. Phase II uses a two-stage MinMax design across 5 cohorts with objective response rate (ORR) as the primary endpoint: NSCLC (ICI naïve, primary refractory, and acquired resistance), SCLC, and thymic carcinoma. Primary refractory is defined as radiographic progression of disease within 12 weeks of ICI initiation. Results: As of January 2021, 75 patients have been enrolled across all cohorts. Stage 1 of the SCLC and primary refractory NSCLC cohorts have completed accrual at 18 and 15 patients, respectively. In the SCLC cohort, disease-control rate (DCR) was 7% and no objective responses were achieved among 14 evaluable patients. In the primary refractory NSCLC cohort, DCR was 57% and ORR 7% (1 partial response) among 14 evaluable patients. A total of 140 treatment-related adverse events (TRAEs) have been reported, 13 (9%) were grade 3 and there were no grade 4/5 events. Fatigue (9%), nausea (6%), diarrhea (6%), ALT elevation (5%), and AST elevation (5%) were the most common all grade TRAEs. The most common grade 3 TRAEs were ALT elevation and hypertension. Conclusions: This therapeutic strategy of nivolumab plus vorolanib appears to be a well-tolerated combination with a manageable safety profile. Adding VEGF inhibition may offer additional disease control in the setting of NSCLC with primary resistance to ICIs, but neither the SCLC or primary refractory NSCLC cohorts achieved the pre-determined target number of objective responses for progression to stage 2 of the study. Enrolment in the other 3 cohorts as well as exploratory correlatives are ongoing. Clinical trial information: NCT03583086.

First-in-Human PET Imaging and Estimated Radiation Dosimetry of l-[5-11C]-Glutamine in Patients with Metastatic Colorectal Cancer

Altered metabolism is a hallmark of cancer. In addition to glucose, glutamine is an important nutrient for cellular growth and proliferation. Noninvasive imaging via PET may help facilitate precision treatment of cancer through patient selection and monitoring of treatment response. l-[5-¹¹C]-glutamine (¹¹C-glutamine) is a PET tracer designed to study glutamine uptake and metabolism. The aim of this first-in-human study was to evaluate the radiologic safety and biodistribution of ¹¹C-glutamine for oncologic PET imaging. Methods: Nine patients with confirmed metastatic colorectal cancer underwent PET/CT imaging. Patients received 337.97 ± 44.08 MBq of ¹¹C-glutamine. Dynamic PET acquisitions that were centered over the abdomen or thorax were initiated simultaneously with intravenous tracer administration. After the dynamic acquisition, a whole-body PET/CT scan was acquired. Volume-of-interest analyses were performed to obtain estimates of organ-based absorbed doses of radiation. Results: ¹¹C-glutamine was well tolerated in all patients, with no observed safety concerns. The organs with the highest radiation exposure included the bladder, pancreas, and liver. The estimated effective dose was 4.46E-03 ± 7.67E-04 mSv/MBq. Accumulation of ¹¹C-glutamine was elevated and visualized in lung, brain, bone, and liver metastases, suggesting utility for cancer imaging. Conclusion: PET using ¹¹C-glutamine appears safe for human use and allows noninvasive visualization of metastatic colon cancer lesions in multiple organs. Further studies are needed to elucidate its potential for other cancers and for monitoring response to treatment.

Factors Affecting Image Quality and Lesion Evaluability in Breast Diffusion-weighted MRI: Observations from the ECOG-ACRIN Cancer Research Group Multisite Trial (A6702)

OBJECTIVE

The A6702 multisite trial confirmed that apparent diffusion coefficient (ADC) measures can improve breast MRI accuracy and reduce unnecessary biopsies, but also found that technical issues rendered many lesions non-evaluable on diffusion-weighted imaging (DWI). This secondary analysis investigated factors affecting lesion evaluability and impact on diagnostic performance.

METHODS

The A6702 protocol was IRB-approved at 10 institutions; participants provided informed consent. In total, 103 women with 142 MRI-detected breast lesions (BI-RADS assessment category 3, 4, or 5) completed the study. DWI was acquired at 1.5T and 3T using a four b-value, echo-planar imaging sequence. Scans were reviewed for multiple quality factors (artifacts, signal-to-noise, misregistration, and fat suppression); lesions were considered non-evaluable if there was low confidence in ADC measurement. Associations of lesion evaluability with imaging and lesion characteristics were determined. Areas under the receiver operating characteristic curves (AUCs) were compared using bootstrapping.

RESULTS

Thirty percent (42/142) of lesions were non-evaluable on DWI; 23% (32/142) with image quality issues, 7% (10/142) with conspicuity and/or localization issues. Misregistration was the only factor associated with non-evaluability (P = 0.001). Smaller (≤10 mm) lesions were more commonly non-evaluable than larger lesions (p <0.03), though not significant after multiplicity correction. The AUC for differentiating benign and malignant lesions increased after excluding non-evaluable lesions, from 0.61 (95% CI: 0.50-0.71) to 0.75 (95% CI: 0.65-0.84).

CONCLUSION

Image quality remains a technical challenge in breast DWI, particularly for smaller lesions. Protocol optimization and advanced acquisition and post-processing techniques would help to improve clinical utility.

Neoadjuvant pazopanib and molecular analysis of tissue response in renal cell carcinoma

BACKGROUNDSurgery remains the frontline therapy for patients with localized clear cell renal cell carcinoma (ccRCC); however, 20%-40% recur. Angiogenesis inhibitors have improved survival in metastatic patients and may result in responses in the neoadjuvant setting. The impact of these agents on the tumor genetic heterogeneity or the immune milieu is largely unknown. This phase II study was designed to evaluate safety, response, and effect on tumor tissue of neoadjuvant pazopanib.METHODSccRCC patients with localized disease received pazopanib (800 mg daily; median 8 weeks), followed by nephrectomy. Five tumors were examined for mutations by whole exome sequencing from samples collected before therapy and at nephrectomy. These samples underwent RNA sequencing; 17 samples were available for posttreatment assessment.RESULTSTwenty-one patients were enrolled. The overall response rate was 8 of 21 (38%). No patients with progressive disease. At 1-year, response-free survival and overall survival was 83% and 89%, respectively. The most frequent grade 3 toxicity was hypertension (33%, 7 of 21). Sequencing revealed strong concordance between pre- and posttreatment samples within individual tumors, suggesting tumors harbor stable core profiles. However, a reduction in private mutations followed treatment, suggesting a selective process favoring enrichment of driver mutations.CONCLUSIONNeoadjuvant pazopanib is safe and active in ccRCC. Future genomic analyses may enable the segregation of driver and passenger mutations. Furthermore, tumor infiltrating immune cells persist during therapy, suggesting that pazopanib can be combined with immune checkpoint inhibitors without dampening the immune response.FUNDINGSupport was provided by Novartis and GlaxoSmithKline as part of an investigator-initiated study.

Mean Apparent Diffusion Coefficient Is a Sufficient Conventional Diffusion-weighted MRI Metric to Improve Breast MRI Diagnostic Performance: Results from the ECOG-ACRIN Cancer Research Group A6702 Diffusion Imaging Trial

Background The Eastern Cooperative Oncology Group and American College of Radiology Imaging Network Cancer Research Group A6702 multicenter trial helped confirm the potential of diffusion-weighted MRI for improving differential diagnosis of suspicious breast abnormalities and reducing unnecessary biopsies. A prespecified secondary objective was to explore the relative value of different approaches for quantitative assessment of lesions at diffusion-weighted MRI. Purpose To determine whether alternate calculations of apparent diffusion coefficient (ADC) can help further improve diagnostic performance versus mean ADC values alone for analysis of suspicious breast lesions at MRI. Materials and Methods This prospective trial (ClinicalTrials.gov identifier: NCT02022579) enrolled consecutive women (from March 2014 to April 2015) with a Breast Imaging Reporting and Data System category of 3, 4, or 5 at breast MRI. All study participants underwent standardized diffusion-weighted MRI (b = 0, 100, 600, and 800 sec/mm²). Centralized ADC measures were performed, including manually drawn whole-lesion and hotspot regions of interest, histogram metrics, normalized ADC, and variable b-value combinations. Diagnostic performance was estimated by using the area under the receiver operating characteristic curve (AUC). Reduction in biopsy rate (maintaining 100% sensitivity) was estimated according to thresholds for each ADC metric. Results Among 107 enrolled women, 81 lesions with outcomes (28 malignant and 53 benign) in 67 women (median age, 49 years; interquartile range, 41-60 years) were analyzed. Among ADC metrics tested, none improved diagnostic performance versus standard mean ADC (AUC, 0.59-0.79 vs AUC, 0.75; P = .02-.84), and maximum ADC had worse performance (AUC, 0.52; P < .001). The 25th-percentile ADC metric provided the best performance (AUC, 0.79; 95% CI: 0.70, 0.88), and a threshold using median ADC provided the greatest reduction in biopsy rate of 23.9% (95% CI: 14.8, 32.9; 16 of 67 BI-RADS category 4 and 5 lesions). Nonzero minimum b value (100, 600, and 800 sec/mm²) did not improve the AUC (0.74; P = .28), and several combinations of two b values (0 and 600, 100 and 600, 0 and 800, and 100 and 800 sec/mm²; AUC, 0.73-0.76) provided results similar to those seen with calculations of four b values (AUC, 0.75; P = .17-.87). Conclusion Mean apparent diffusion coefficient calculated with a two-b-value acquisition is a simple and sufficient diffusion-weighted MRI metric to augment diagnostic performance of breast MRI compared with more complex approaches to apparent diffusion coefficient measurement. © RSNA, 2020 Online supplemental material is available for this article.

Supporting Clinical Decision-Making during the SARS-CoV-2 Pandemic through a Global Research Commitment: The TERAVOLT Experience

To understand the real impact of COVID-19 on cancer patients, an entirely new data collection effort was initiated within the Thoracic Cancers International COVID-19 Collaboration (TERAVOLT). TERAVOLT reported high mortality related to COVID-19 infection in thoracic cancer patients and identified several negative prognostic factors. In this commentary, we discuss the importance and limits of patient registries to support decision-making in thoracic cancer during the SARS-CoV-2 pandemic.

Abstract S12-03: Thoracic cancers international COVID-19 collaboration (TERAVOLT): Small-cell lung cancer and other rare thoracic malignancies

Background: At the last update of the TERAVOLT registry, patients with thoracic malignancies and COVID-19 showed a high mortality rate (35.5% overall and 31% due to COVID-19) compared to the general population and to other solid tumors. Major determinants of mortality were age, Eastern Cooperative Oncology Group Performance Status (ECOG-PS), and previous administration of chemotherapy. No cancer-specific data are available with respect to small-cell lung cancer (SCLC) and other rare thoracic malignancies.

Methods: TERAVOLT is an international, multicenter observational registry launched to collect data on patients with thoracic malignancies diagnosed with COVID-19 infection. Risk factors for hospitalization and mortality were identified by Wilcoxon rank sum tests (continuous variables) or χ2 tests (categorical variables). Here we present the subgroup analyses of SCLC and other rare thoracic malignancies, including malignant pleural mesothelioma (MPM), thymic carcinoma/thymoma, and carcinoid/neuroendocrine lung tumors.

Results: As of June 4th, 2020, a total of 581 patients with COVID-19 and thoracic cancers have been entered; among them, 66 (11%) were SCLC, 22 (4%) were MPM, 18 (3%) were thymic carcinoma/thymoma, 12 (2%) were carcinoid/neuroendocrine lung tumors, and 442 (76%) NSCLC; 21 were an unknown type. Among SCLC patients, 54% were &gt; 65 years old, 56% were males, 98% were current/former smokers, 31% had an ECOG-PS ≥ 2, 67% had stage IV disease, 82% were on current oncologic treatment at the COVID-19 diagnosis, and 58% were receiving chemotherapy alone or in combination with immune checkpoint inhibitors. Among other non-NSCLC patients, 56% were &gt; 65 years old, 56% were males, 69% were current/former smokers, 24% had an ECOG-PS ≥ 2, 50% had stage IV disease, 52% were on current oncologic treatment at the COVID-19 diagnosis, and 37% were receiving chemotherapy alone or in combination with immune checkpoint inhibitors. Overall, 79.7% of the patients required hospitalization, 15.4% were admitted to an ICU, and 39.8% died (36.2% due to COVID-19). Among SCLC patients, 74.2% required hospitalization, 14.3% were admitted to an ICU, and 42.2% died (37.5% due to COVID-19). Among SCLC patients, age &gt; 65 years old (p=0.81), gender (p=0.71), smoking status (p=1.0), ECOG-PS ≥ 2(p=0.17), disease stage of IV (p=0.37), and having received chemotherapy alone or with checkpoint inhibitors (p=0.84) were not associated with mortality.

Conclusions: This analysis confirmed that patients with thoracic malignancies have a high mortality and risk for hospitalization due to COVID-19 overall. SCLC patients showed the highest mortality rate among thoracic cancer patients.

Citation Format: Alessio Cortellini, Anne-Marie C. Dingemans, Oscar Arrieta, Javier Baena, Matteo Brighenti, Enriqueta Felip, Marina Chiara Garassino, Pilar Garrido, Carlo Genova, Federica Grosso, Leora Horn, Li-Ching Huang, Jan Van Meerbeeck, Solange Peters, Ernest Nadal, Jacobo Rogado, Yu Shyr, Marcello Tiseo, Valter Torri, Annalisa Trama, Heather Wakelee, Jennifer G Whisenant, Giuseppe Viscardi, Fabrice Barlesi, Sanjay Popat. Thoracic cancers international COVID-19 collaboration (TERAVOLT): Small-cell lung cancer and other rare thoracic malignancies [abstract]. In: Proceedings of the AACR Virtual Meeting: COVID-19 and Cancer; 2020 Jul 20-22. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(18_Suppl):Abstract nr S12-03.

Multiparametric Analysis of Longitudinal Quantitative MRI data to Identify Distinct Tumor Habitats in Preclinical Models of Breast Cancer

This study identifies physiological tumor habitats from quantitative magnetic resonance imaging (MRI) data and evaluates their alterations in response to therapy. Two models of breast cancer (BT-474 and MDA-MB-231) were imaged longitudinally with diffusion-weighted MRI and dynamic contrast-enhanced MRI to quantify tumor cellularity and vascularity, respectively, during treatment with trastuzumab or albumin-bound paclitaxel. Tumors were stained for anti-CD31, anti-Ki-67, and H&E. Imaging and histology data were clustered to identify tumor habitats and percent tumor volume (MRI) or area (histology) of each habitat was quantified. Histological habitats were correlated with MRI habitats. Clustering of both the MRI and histology data yielded three clusters: high-vascularity high-cellularity (HV-HC), low-vascularity high-cellularity (LV-HC), and low-vascularity low-cellularity (LV-LC). At day 4, BT-474 tumors treated with trastuzumab showed a decrease in LV-HC (p = 0.03) and increase in HV-HC (p = 0.03) percent tumor volume compared to control. MDA-MB-231 tumors treated with low-dose albumin-bound paclitaxel showed a longitudinal decrease in LV-HC percent tumor volume at day 3 (p = 0.01). Positive correlations were found between histological and imaging-derived habitats: HV-HC (BT-474: p = 0.03), LV-HC (MDA-MB-231: p = 0.04), LV-LC (BT-474: p = 0.04; MDA-MB-231: p < 0.01). Physiologically distinct tumor habitats associated with therapeutic response were identified with MRI and histology data in preclinical models of breast cancer.

Thoracic Cancers International COVID-19 Collaboration (TERAVOLT): Impact of type of cancer therapy and COVID therapy on survival

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Background: Early reports on cancer patients infected with COVID-19 have suggested a high mortality rate compared to the general population. Patients with thoracic malignancies are considered high risk given their age, preexisting comorbidities, smoking, and pre-existing lung damage in addition to therapies administered to treat their illness. Method: We launched a global consortium to collect data on patients with thoracic malignancies diagnosed with COVID-19 infection to understand the impact on this patient population. Goals of this consortium are to provide data for guidance to oncology professionals on treating patients with thoracic malignancies while understanding the risk factors for morbidity and mortality from this novel virus. Results: As of April 23, 2020, a total of 295 patients across 59 centers and 9 countries have been entered; median age 68, 31% female, 79% current/former smokers, HTN and COPD most common comorbidities; 73% NSCLC, 14% SCLC, 4% meso and thymic, 49% patients with stage IV disease, majority on chemo or chemo-IO and 24% receiving RT. The use of IO or chemo-IO does not appear to impact risk of hospitalization, while treatment with TKI appears to be associated with a decreased risk of hospitalization. 73% patients required hospitalization, most common therapy given to treat COVID was antibiotics 67%, antivirals 33%, and steroids 30%. Conclusion: With an ongoing global pandemic of COVID-19 our data suggest that patients with thoracic malignancies are at high risk for hospitalization. Updated results to be presented will include impact on specific chemo-IO regimens and number of lines of therapy, which may impact hospitalization and risk of death as well as which therapies administered may impact survival in patients treated for COVID-19.

Quantitative Comparison of Prone and Supine PERCIST Measurements in Breast Cancer

Positron emission tomography (PET) is typically performed in the supine position. However, breast magnetic resonance imaging (MRI) is performed in prone, as this improves visibility of deep breast tissues. With the emergence of hybrid scanners that integrate molecular information from PET and functional information from MRI, it is of great interest to determine if the prognostic utility of prone PET is equivalent to supine. We compared PERCIST (PET Response Criteria in Solid Tumors) measurements between prone and supine FDG-PET in patients with breast cancer and the effect of orientation on predicting pathologic complete response (pCR). In total, 47 patients were enrolled and received up to 6 cycles of neoadjuvant therapy. Prone and supine FDG-PET were performed at baseline (t₀; n = 46), after cycle 1 (t₁; n = 1) or 2 (t₂; n = 10), or after all neoadjuvant therapy (t₃; n = 19). FDG uptake was quantified by maximum and peak standardized uptake value (SUV) with and without normalization to lean body mass; that is, SUV_max, SUV_peak, SUL_max, and SUL_peak. PERCIST measurements were performed for each paired baseline and post-treatment scan. Receiver operating characteristic analysis for the prediction of pCR was performed using logistic regression that included age and tumor size as covariates. SUV and SUL metrics were significantly different between orientation (P < .001), but were highly correlated (P > .98). Importantly, no differences were observed with the PERCIST measurements (P > .6). Overlapping 95% confidence intervals for the receiver operating characteristic analysis suggested no difference at predicting pCR. Therefore, prone and supine PERCIST in this data set were not statistically different.

TERAVOLT: Thoracic Cancers International COVID-19 Collaboration

Prior publications on small subsets of cancer patients infected with SARS CoV-2 have shown an increased risk of mortality compared to the general population. Furthermore, patients with thoracic malignancies are thought to be at particularly high risk given their older age, smoking habits, and pre-existing cardio-pulmonary comorbidities. For this reason, physicians around the world have formed TERAVOLT, a global consortium dedicated to understanding the impact of COVID-19 on patients with thoracic malignancies.

Phase I/II study of vorolanib plus nivolumab in patients with thoracic malignancies: immunotherapy (IO) correlatives to differentiate responders from nonresponders

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Background: VEGF inhibition is suggested to enhance innate T cell function, activate dendritic cells, block recruitment of regulatory T cells, and decrease myeloid-derived suppressor cells. Vorolanib is a tyrosine kinase inhibitor that is structurally similar to sunitinib but designed to improve safety without compromising efficacy. Response to checkpoint inhibitors in patients with thoracic tumors is limited, thus we designed this multi-institutional, phase I/II study (NCT03583086) to explore safety and efficacy of combining vorolanib and nivolumab. Here we present updated results in the NSCLC, thymic, and SCLC cohorts, including patients previously treated with single agent IO. Methods: The Phase I maximum tolerated dose was 200 mg vorolanib and 240 mg nivolumab q2w. Phase II is ongoing and uses a two-stage MinMax design to assess the objective response rate (RR) in SCLC, thymic carcinoma, and three NSCLC cohorts: 1) IO naïve; 2) primary refractory, defined as radiographic progression < 12 weeks of starting IO; and 3) acquired resistance, defined as achieving at least stable disease ≥12 weeks to IO followed by progression. Results: As of December 2019, 37 patients had enrolled, 38% female, 11% never smokers, median age 66. The disease control rate (DCR) across all cohorts is 65% (20/31 evaluable patients) and the RR is 13% (4/31). In the NSCLC cohort, the overall RR is 14% (3/21); the RR is 33% (2/6) in IO naïve patients, including 2 on therapy > 17 months. RR in the NSCLC patients with acquired resistance is 14% (1/7) with an 86% (6/7) DCR. No responses in the primary refractory cohort but the DCR is 50% (4/8). DCR in the SCLC and thymic cohorts is 40% (2/5) and 50% (2/4), respectively; 1 thymic patient had a partial response with a complete response in target lesions. Exploratory correlatives, including mass cytometry analysis and single cell gene expression, are being performed in order to understand changes in macrophages and T cell activation markers to differentiate the underlying biology of the tumor and the microenvironment between responders and nonresponders. Conclusions: The addition of vorolanib nearly doubled the RR in the IO naïve NSCLC patients compared to historical data with single agent nivolumab. Additionally, 67% of NSCLC patients with prior IO achieved at least stable disease, 1 patient with acquired resistance had a response. Correlatives that may help define biomarkers of response to therapy will be presented among different cohorts of patients. Clinical trial information: NCT03583086 .

Translating preclinical MRI methods to clinical oncology

The complexity of modern in vivo magnetic resonance imaging (MRI) methods in oncology has dramatically changed in the last 10 years. The field has long since moved passed its (unparalleled) ability to form images with exquisite soft-tissue contrast and morphology, allowing for the enhanced identification of primary tumors and metastatic disease. Currently, it is not uncommon to acquire images related to blood flow, cellularity, and macromolecular content in the clinical setting. The acquisition of images related to metabolism, hypoxia, pH, and tissue stiffness are also becoming common. All of these techniques have had some component of their invention, development, refinement, validation, and initial applications in the preclinical setting using in vivo animal models of cancer. In this review, we discuss the genesis of quantitative MRI methods that have been successfully translated from preclinical research and developed into clinical applications. These include methods that interrogate perfusion, diffusion, pH, hypoxia, macromolecular content, and tissue mechanical properties for improving detection, staging, and response monitoring of cancer. For each of these techniques, we summarize the 1) underlying biological mechanism(s); 2) preclinical applications; 3) available repeatability and reproducibility data; 4) clinical applications; and 5) limitations of the technique. We conclude with a discussion of lessons learned from translating MRI methods from the preclinical to clinical setting, and a presentation of four fundamental problems in cancer imaging that, if solved, would result in a profound improvement in the lives of oncology patients. Level of Evidence: 5 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2019;50:1377-1392.

Monitoring Therapeutic Response and Resistance: Analysis of Circulating Tumor DNA in Patients With ALK+ Lung Cancer

INTRODUCTION

Despite initial effectiveness of ALK receptor tyrosine kinase inhibitors (TKIs) in patients with ALK+ NSCLC, therapeutic resistance will ultimately develop. Serial tracking of genetic alterations detected in circulating tumor DNA (ctDNA) can be an informative strategy to identify response and resistance. This study evaluated the utility of analyzing ctDNA as a function of response to ensartinib, a potent second-generation ALK TKI.

METHODS

Pre-treatment plasma was collected from 76 patients with ALK+ NSCLC who were ALK TKI-naive or had received prior ALK TKI, and analyzed for specific genetic alterations. Longitudinal plasma samples were analyzed from a subset (n = 11) of patients. Analysis of pre-treatment tumor biopsy specimens from 22 patients was compared with plasma.

RESULTS

Disease-associated genetic alterations were detected in 74% (56 of 76) of patients, the most common being EML4-ALK. Concordance of ALK fusion between plasma and tissue was 91% (20 of 22 blood and tissue samples). Twenty-four ALK kinase domain mutations were detected in 15 patients, all had previously received an ALK TKI; G1269A was the most prevalent (4 of 24). Patients with a detectable EML4-ALK variant 1 (V1) fusion had improved response (9 of 17 patients; 53%) to ensartinib compared to patients with EML4-ALK V3 fusion (one of seven patients; 14%). Serial changes in ALK alterations were observed during therapy.

CONCLUSIONS

Clinical utility of ctDNA was shown, both at pre-treatment by identifying a potential subgroup of ALK+ NSCLC patients who may derive more benefit from ensartinib and longitudinally by tracking resistance. Prospective application of this technology may translate to improved outcomes for NSCLC patients treated with ALK TKIs.

Abstract CT171: Phase I/II study to evaluate the safety and preliminary activity of nivolumab in combination with vorolanib in patients with refractory thoracic tumors

Background: Nivolumab monotherapy results in limited responses (19-25%) in thoracic tumors, therefore the potential exists to design combination strategies to improve tumor response. Evidence exists to suggest that antiangiogenic agents have the potential to stimulate the immune system. Several pilot trials combined inhibitors of PD-1/PD-L1 and VEGFR in renal cell carcinoma, and the combinations outperformed either single agent. However, none of the combinations were well tolerated at full doses of the drugs. Therefore, it is desirable to explore immunotherapy and antiangiogenic agent combinations that have lower toxicity. Vorolanib is structurally similar to the antiangiogenic agent sunitinib but was designed to improve the safety profile without compromising efficacy. Preclinically, vorolanib had comparable anti-tumor activity to sunitinib, and toxicokinetic analyses suggested a very high safety window.

Methods: NCT03583086 is a multi-institutional, phase I/II study of nivolumab and vorolanib in patients with thoracic tumors who failed at least one prior line of chemotherapy. The primary objective of phase I is to determine the maximum tolerated dose. Dose escalation uses a standard 3+3 design with three dose levels of vorolanib (200, 300, and 400 mg once-daily) and 240 mg nivolumab every two weeks. Phase II evaluates efficacy of the combination among five cohorts: immunotherapy naïve non-small cell lung cancer (NSCLC), NSCLC patients that have progressed (primary refractory and acquired resistance) on immunotherapy, thymic carcinoma, and small cell lung cancer (SCLC) patients with progression on prior platinum-based chemotherapy. Primary refractory is defined as radiographic progression of disease within 12 weeks after initiation of checkpoint therapy; acquired resistance includes achieving radiographic partial or complete response, or stable disease for at least 12 weeks followed by radiographic disease progression. Enrollment to phase II will use a Simon two-stage design for each cohort. Exploratory objectives will be performed to quantify changes in the innate and adaptive immune responses after treatment. Mass cytometry will be used to monitor serial changes in multiple immune markers on individual circulating cells in the blood. Changes in each marker will be correlated with response using the Lasso-based elastic net method. Single cell gene expression analysis from peripheral blood samples collected prior to and at the end of treatment will be performed and correlated with response to combination therapy in order to improve our understanding of the biology behind systemic changes to this treatment. Enrollment to phase I is ongoing; 7 patients have been enrolled, including 3 in dose cohort 1 and 4 in dose cohort 2. Thus far, a dose-limiting toxicity of elevated liver function tests possibly related to nivolumab and vorolanib was observed in one patient enrolled in dose cohort 2.

Citation Format: Jennifer G. Whisenant, Katy Beckerman, Hossein Borghaei, Taofeek Owonikoko, Jyoti Patel, Yu Shyr, Kimberly Harrow, Chris Liang, Allison Holzhausen, Heather Wakelee, Leora Horn. Phase I/II study to evaluate the safety and preliminary activity of nivolumab in combination with vorolanib in patients with refractory thoracic tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr CT171.

Characterizing Trastuzumab-Induced Alterations in Intratumoral Heterogeneity with Quantitative Imaging and Immunohistochemistry in HER2+ Breast Cancer

The purpose of this study is to investigate imaging and histology-based measurements of intratumoral heterogeneity to evaluate early treatment response to targeted therapy in a murine model of HER2+ breast cancer. BT474 tumor-bearing mice (N = 30) were treated with trastuzumab or saline and imaged longitudinally with either dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) or 18F-fluoromisonidazole (FMISO) positron emission tomography (PET). At the imaging study end point (day 4 for MRI or 7 for PET), each tumor was excised for immunohistochemistry analysis. Voxel-based histogram analysis was performed on imaging-derived parametric maps (i.e., Ktrans and ve from DCE-MRI, SUV from 18F-FMISO-PET) of the tumor region of interest to measure heterogeneity. Image processing and histogram analysis of whole tumor slice immunohistochemistry data were performed to validate the in vivo imaging findings. Trastuzumab-treated tumors had increased heterogeneity in quantitative imaging measures of cellularity (ve), with a mean Kolmogorov-Smirnov (K-S) distance of 0.32 (P = .05) between baseline and end point distributions. Trastuzumab-treated tumors had increased vascular heterogeneity (Ktrans) and decreased hypoxic heterogeneity (SUV), with a mean K-S distance of 0.42 (P < .01) and 0.46 (P = .047), respectively, between baseline and study end points. These observations were validated by whole-slice immunohistochemistry analysis with mean interquartile range of CD31 distributions of 1.72 for treated and 0.95 for control groups (P = .02). Quantitative longitudinal changes in tumor cellular and vascular heterogeneity in response to therapy may provide evidence for early prediction of response and guide therapy for patients with HER2+ breast cancer.

Phase I study combining the aurora kinase a inhibitor alisertib with mFOLFOX in gastrointestinal cancer

Overexpression and cellular mis-localization of aurora kinase A (AURKA) in gastrointestinal cancers results in chromosomal instability, activation of multiple oncogenic pathways, and inhibition of pro-apoptotic signaling. Inhibition of AURKA causes mitotic delays, severe chromosome congression, and activation of p53/p73 leading to cell death. Our preclinical data showed cooperative activity with the AURKA inhibitor alisertib and platinum agents in cell lines and xenografts, and suggested an optimal treatment window. Therefore, this study was designed to determine the maximum-tolerated dose (MTD) of alisertib in combination with modified FOLFOX (mFOLFOX), as this is a standard platinum-based therapy for gastrointestinal cancers. Standard 3 + 3 dose escalation was used, where the starting dose of alisertib was 10 mg twice daily (Days 1-3), with leucovorin (400 mg/m²) and oxaliplatin (85 mg/m²) on Day 2 followed by continuous 46-h 5-FU (2400 mg/m²) infusion on Days 2-4 in 14-day cycles. Fourteen patients with advanced gastrointestinal cancers were enrolled and two doses explored; two patients were not evaluable for dose-limiting toxicity (DLT) and replaced. Two patients experienced DLTs at 20 mg of alisertib (Grade 3 fatigue (n = 2); Grade 3 nausea, vomiting, dehydration with hospitalization (n = 1)). MTD was 10 mg alisertib with 85 mg/m² oxaliplatin and 2400 mg/m² 5-FU. Most frequent toxicities were nausea (57%), diarrhea, fatigue, neuropathy, and vomiting (43%), and anorexia and anemia (36%); most were Grade 1-2. One patient with colorectal cancer had a partial response of 12 evaluable patients, and four patients had stable disease. Alisertib in combination with mFOLFOX did not demonstrate unexpected side effects, but the regimen was only tolerable at the lowest dose investigated.

A Phase II Study of Ganetespib as Second-line or Third-line Therapy for Metastatic Pancreatic Cancer

OBJECTIVES

Heat shock protein 90 regulates multiple signaling proteins involved in key pathways of pancreatic cancer pathogenesis. Ganetespib binds to heat shock protein 90 and interferes with its binding to client proteins thus leading to inactivation and degradation of the signaling proteins that promote cancer progression. This phase II study was designed to evaluate the efficacy of ganetespib in patients with refractory metastatic pancreatic cancer (rMPC).

METHODS

Patients with rMPC received 175 mg/m ganetespib intravenously once weekly for 3 weeks in 4-week cycles. Primary endpoint was disease control rate at 8 weeks, with a goal of 70%. Secondary endpoints were progression-free survival, overall survival, and safety. Simon's 2-stage design was used to assess futility and efficacy. Ganetespib was considered inactive if ≤8 patients among the first 15 treated had disease control after 8 weeks of treatment.

RESULTS

Fourteen patients were treated on study. Grade 3 treatment-related toxicities were diarrhea, abdominal pain, fatigue, nausea, vomiting, and hyponatremia. Disease control rate at 8 weeks was 28.6%, and median progression-free survival and overall survival were 1.58 months and 4.57 months, respectively. Early stopping rules for lack of clinical efficacy led to study closure.

CONCLUSIONS

Single-agent ganetespib was tolerable with only modest disease control in rMPC. This disease is resistant to chemotherapy, and given the emerging data in lung and rectal cancers, as well as in pancreatic cancer cell lines, suggesting improved activity of ganetespib in combination with cytotoxic agents, studies combining this agent with chemotherapy in rMPC are more likely to yield success.

Ensartinib (X-396) in ALK-Positive Non-Small Cell Lung Cancer: Results from a First-in-Human Phase I/II, Multicenter Study

Purpose: Evaluate safety and determine the recommended phase II dose (RP2D) of ensartinib (X-396), a potent anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitor (TKI), and evaluate preliminary pharmacokinetics and antitumor activity in a first-in-human, phase I/II clinical trial primarily in patients with non-small cell lung cancer (NSCLC).Patients and Methods: In dose escalation, ensartinib was administered at doses of 25 to 250 mg once daily in patients with advanced solid tumors; in dose expansion, patients with advanced ALK-positive NSCLC were administered 225 mg once daily. Patients who had received prior ALK TKI(s) and patients with brain metastases were eligible.Results: Thirty-seven patients enrolled in dose escalation, and 60 enrolled in dose expansion. The most common treatment-related toxicities were rash (56%), nausea (36%), pruritus (28%), vomiting (26%), and fatigue (22%); 23% of patients experienced a treatment-related grade 3 to 4 toxicity (primarily rash and pruritus). The maximum tolerated dose was not reached, but the RP2D was chosen as 225 mg based on the frequency of rash observed at 250 mg without improvement in activity. Among the ALK-positive efficacy evaluable patients treated at ≥200 mg, the response rate (RR) was 60%, and median progression-free survival (PFS) was 9.2 months. RR in ALK TKI-naïve patients was 80%, and median PFS was 26.2 months. In patients with prior crizotinib only, the RR was 69% and median PFS was 9.0 months. Responses were also observed in the central nervous system, with an intracranial RR of 64%.Conclusions: Ensartinib was active and generally well tolerated in patients with ALK-positive NSCLC. Clin Cancer Res; 24(12); 2771-9. ©2018 AACR.

Dual Src and EGFR inhibition in combination with gemcitabine in advanced pancreatic cancer: phase I results : A phase I clinical trial

Pancreatic adenocarcinoma remains a major therapeutic challenge, as the poor (<8%) 5-year survival rate has not improved over the last three decades. Our previous preclinical data showed cooperative attenuation of pancreatic tumor growth when dasatinib (Src inhibitor) was added to erlotinib (EGFR inhibitor) and gemcitabine. Thus, this study was designed to determine the maximum-tolerated dose of the triplet combination. Standard 3 + 3 dose escalation was used, starting with daily oral doses of 70 mg dasatinib and 100 mg erlotinib with gemcitabine on days 1, 8, and 15 (800 mg/m²) of a 28-day cycle (L₀). Nineteen patients were enrolled, yet 18 evaluable for dose-limiting toxicities (DLTs). One DLT observed at L₀, however dasatinib was reduced to 50 mg (L_-1) given side effects observed in the first two patients. At L_-1, a DLT occurred in 1/6 patients and dose was re-escalated to L₀, where zero DLTs reported in next four patients. Dasatinib was escalated to 100 mg (L₁) where 1/6 patients experienced a DLT. Although L₁ was tolerable, dose escalation was stopped as investigators felt L₁ was within the optimal therapeutic window. Most frequent toxicities were anemia (89%), elevated aspartate aminotransferase (79%), fatigue (79%), nausea (79%), elevated alanine aminotransferase (74%), lymphopenia (74%), leukopenia (74%), neutropenia (63%), and thrombocytopenia (63%), most Grade 1/2. Stable disease as best response was observed in 69% (9/13). Median progression-free and overall survival was 3.6 and 8 months, respectively. Dasatinib, erlotinib, and gemcitabine was safe with manageable side effects, and with encouraging preliminary clinical activity in advanced pancreatic cancer.

First-in-human phase I dose escalation study of MK-8033 in patients with advanced solid tumors

Background C-Met, which is frequently activated in multiple cancers, has been implicated in tumor formation, progression, metastasis, angiogenesis, and resistance to multiple therapies. MK-8033 is a small-molecule inhibitor of c-Met that binds preferentially to the activated conformation, and has demonstrated anti-tumor activity in preclinical models. This first-in-human trial was performed to establish the safety and maximum tolerated dose (MTD), as well as preliminary pharmacokinetics (PK) and clinical activity. Methods Forty-seven patients were enrolled in three parts. The primary objective of Parts A and B was safety, whereas Part C evaluated the effect of proton-pump inhibitors on MK-8033 absorption. Dose escalation used an accelerated continual reassessment method, and dose-limiting toxicities (DLTs) were any treatment-related, first course non-hematologic grade ≥ 3 toxicity (except alopecia or inadequately treated nausea/vomiting/diarrhea), grade 4 hematologic toxicity (except grade 3 neutropenic fever and thrombocytopenia), or toxicity where treatment is held >3 weeks. Results Forty-six patients were treated across nine dose levels, and the MTD was 750 mg twice daily. DLTs were fatigue, nausea, vomiting, transaminitis, and hypokalemia. Most frequent toxicities were fatigue (28.3%), nausea (21.7%), and alopecia (19.6%), predominately grade ≤ 2. One patient with endometriod adenocarcinoma achieved a partial response and eight had stable disease. Median progression-free survival (PFS) was 57 days. Strikingly, the PFS for the one responder was 846 days. PK results showed that proton-pump inhibitors have no effect on MK-8033 absorption. Conclusion MK-8033 was well tolerated with no significant toxicity issues, albeit with limited clinical activity. Unfortunately, the company decided to discontinue further clinical development of MK-8033.

DCE- and DW-MRI as early imaging biomarkers of treatment response in a preclinical model of triple negative breast cancer

This work evaluates quantitative dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and diffusion-weighted MRI (DW-MRI) parameters as early biomarkers of response in a preclinical model of triple negative breast cancer (TNBC). The standard Tofts' model of DCE-MRI returns estimates of the volume transfer constant (K^trans ) and the extravascular extracellular volume fraction (v_e ). DW-MRI returns estimates of the apparent diffusion coefficient (ADC). Mice (n = 38) were injected subcutaneously with MDA-MB-231. Tumors were grown to approximately 275 mm³ and sorted into the following groups: saline controls, low-dose Abraxane (15 mg/kg) and high-dose Abraxane (25 mg/kg). Animals were imaged at days zero, one and three. On day three, tumors were extracted for immunohistochemistry. The positive percentage change in ADC on day one was significantly higher in both treatment groups relative to the control group (p < 0.05). In addition, the positive percentage change in K^trans was significantly higher than controls (p < 0.05) on day one for the high-dose group and on days one and three for the low-dose group. The percentage change in tumor volume was significantly different between the high-dose and control groups on day three (p = 0.006). Histology confirmed differences at day three through reduced numbers of proliferating cells (Ki67 staining) in the high-dose group (p = 0.03) and low-dose group (p = 0.052) compared with the control group. Co-immunofluorescent staining of vascular maturity [using von Willebrand Factor (vWF) and α-smooth muscle actin (α-SMA)] indicated significantly higher vascular maturation in the low-dose group compared with the controls on day three (p = 0.03), and trending towards significance in the high-dose group compared with controls on day three (p = 0.052). These results from quantitative imaging with histological validation indicate that ADC and K^trans have the potential to serve as early biomarkers of treatment response in murine studies of TNBC.

Quantitative Magnetization Transfer Imaging of the Breast at 3.0 T: Reproducibility in Healthy Volunteers

Quantitative magnetization transfer magnetic resonance imaging provides a means for indirectly detecting changes in the macromolecular content of tissue noninvasively. A potential application is the diagnosis and assessment of treatment response in breast cancer; however, before quantitative magnetization transfer imaging can be reliably used in such settings, the technique's reproducibility in healthy breast tissue must be established. Thus, this study aims to establish the reproducibility of the measurement of the macromolecular-to-free water proton pool size ratio (PSR) in healthy fibroglandular (FG) breast tissue. Thirteen women with no history of breast disease were scanned twice within a single scanning session, with repositioning between scans. Eleven women had appreciable FG tissue for test–retest measurements. Mean PSR values for the FG tissue ranged from 9.5% to 16.7%. The absolute value of the difference between 2 mean PSR measurements for each volunteer ranged from 0.1% to 2.1%. The 95% confidence interval for the mean difference was ±0.75%, and the repeatability value was 2.39%. These results indicate that the expected measurement variability would be ±0.75% for a cohort of a similar size and would be ±2.39% for an individual, suggesting that future studies of change in PSR in patients with breast cancer are feasible.

Bloch-Siegert B1-Mapping Improves Accuracy and Precision of Longitudinal Relaxation Measurements in the Breast at 3 T

Variable flip angle (VFA) sequences are a popular method of calculating T₁ values, which are required in a quantitative analysis of dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI). B₁ inhomogeneities are substantial in the breast at 3 T, and these errors negatively impact the accuracy of the VFA approach, thus leading to large errors in the DCE-MRI parameters that could limit clinical adoption of the technique. This study evaluated the ability of Bloch–Siegert B₁ mapping to improve the accuracy and precision of VFA-derived T₁ measurements in the breast. Test–retest MRI sessions were performed on 16 women with no history of breast disease. T₁ was calculated using the VFA sequence, and B₁ field variations were measured using the Bloch–Siegert methodology. As a gold standard, inversion recovery (IR) measurements of T₁ were performed. Fibroglandular tissue and adipose tissue from each breast were segmented using the IR images, and the mean T₁ was calculated for each tissue. Accuracy was evaluated by percent error (%err). Reproducibility was assessed via the 95% confidence interval (CI) of the mean difference and repeatability coefficient (r). After B₁ correction, %err significantly (P < .001) decreased from 17% to 8.6%, and the 95% CI and r decreased from ±94 to ±38 milliseconds and from 276 to 111 milliseconds, respectively. Similar accuracy and reproducibility results were observed in the adipose tissue of the right breast and in both tissues of the left breast. Our data show that Bloch–Siegert B₁ mapping improves accuracy and precision of VFA-derived T₁ measurements in the breast.

A phase I trial investigating pulsatile erlotinib in combination with gemcitabine and oxaliplatin in advanced biliary tract cancers

Advanced biliary tract cancers (ABTC) are among the deadliest malignancies with limited treatment options after progression on standard-of-care chemotherapy, which includes gemcitabine (GEM) and oxaliplatin (OX). The epidermal growth factor receptor inhibitor erlotinib has been explored in ABTC with modest efficacy. Erlotinib given continuously may antagonize the action of chemotherapy against cycling tumor cells, but pulsatile dosing of erlotinib with chemotherapy may improve efficacy. The purpose of this study was to assess the safety of pulsatile erlotinib with GEMOX. This was a single-institution phase Ib study that enrolled adult patients with unresectable or metastatic biliary tract, pancreas, duodenal, or ampullary carcinomas that have not received any prior treatment for their disease. Dose escalation followed a standard 3 + 3 design, and dose-limiting toxicities (DLTs) were any treatment-related, first course non-hematologic grade ≥ 3 toxicity, except nausea/vomiting, or grade 4 hematologic toxicity. A dose expansion cohort in ABTC was treated at the MTD. Twenty-eight patients were enrolled and 4 dose levels were explored. The MTD was erlotinib 150 mg + GEM 800 mg/m² + OX 85 mg/m². DLTs were diarrhea and anemia. Most frequent toxicities were nausea (78 %), fatigue (71 %), neuropathy (68 %), and diarrhea (61 %), predominantly grade 1–2. In the ABTC patients, the objective response and disease control rates were 29 % and 94 %, respectively, and median overall survival was 18 months. Erlotinib plus GEMOX was well tolerated. Encouraging anti-tumor activity was seen as evidenced by a high disease control rate and longer median OS than standard chemotherapy in the patients with ABTC.

MR Imaging Biomarkers in Oncology Clinical Trials

The authors discuss eight areas of quantitative MR imaging that are currently used (RECIST, DCE-MR imaging, DSC-MR imaging, diffusion MR imaging) in clinical trials or emerging (CEST, elastography, hyperpolarized MR imaging, multiparameter MR imaging) as promising techniques in diagnosing cancer and assessing or predicting response of cancer to therapy. Illustrative applications of the techniques in the clinical setting are summarized before describing the current limitations of the methods.

Comparison of prone versus supine 18F-FDG-PET of locally advanced breast cancer: Phantom and preliminary clinical studies

PURPOSE

Previous studies have demonstrated how imaging of the breast with patients lying prone using a supportive positioning device markedly facilitates longitudinal and/or multimodal image registration. In this contribution, the authors' primary objective was to determine if there are differences in the standardized uptake value (SUV) derived from [(18)F]fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) in breast tumors imaged in the standard supine position and in the prone position using a specialized positioning device.

METHODS

A custom positioning device was constructed to allow for breast scanning in the prone position. Rigid and nonrigid phantom studies evaluated differences in prone and supine PET. Clinical studies comprised 18F-FDG-PET of 34 patients with locally advanced breast cancer imaged in the prone position (with the custom support) followed by imaging in the supine position (without the support). Mean and maximum values (SUVpeak and SUVmax, respectively) were obtained from tumor regions-of-interest for both positions. Prone and supine SUV were linearly corrected to account for the differences in 18F-FDG uptake time. Correlation, Bland-Altman, and nonparametric analyses were performed on uptake time-corrected and uncorrected data.

RESULTS

SUV from the rigid PET breast phantom imaged in the prone position with the support device was 1.9% lower than without the support device. In the nonrigid PET breast phantom, prone SUV with the support device was 5.0% lower than supine SUV without the support device. In patients, the median (range) difference in uptake time between prone and supine scans was 16.4 min (13.4-30.9 min), which was significantly-but not completely-reduced by the linear correction method. SUVpeak and SUVmax from prone versus supine scans were highly correlated, with concordance correlation coefficients of 0.91 and 0.90, respectively. Prone SUVpeak and SUVmax were significantly lower than supine in both original and uptake time-adjusted data across a range of index times (P < < 0.0001, Wilcoxon signed rank test). Before correcting for uptake time differences, Bland-Altman analyses revealed proportional bias between prone and supine measurements (SUVpeak and SUVmax) that increased with higher levels of FDG uptake. After uptake time correction, this bias was significantly reduced (P < 0.01). Significant prone-supine differences, with regard to the spatial distribution of lesions relative to isocenter, were observed between the two scan positions, but this was poorly correlated with the residual (uptake time-corrected) prone-supine SUVpeak difference (P = 0.78).

CONCLUSIONS

Quantitative 18F-FDG-PET/CT of the breast in the prone position is not deleteriously affected by the support device but yields SUV that is consistently lower than those obtained in the standard supine position. SUV differences between scans arising from FDG uptake time differences can be substantially reduced, but not removed entirely, with the current correction method. SUV from the two scan orientations is quantitatively different and should not be assumed equivalent or interchangeable within the same subject. These findings have clinical relevance in that they underscore the importance of patient positioning while scanning as a clinical variable that must be accounted for with longitudinal PET measurement, for example, in the assessment of treatment response.

Trastuzumab improves tumor perfusion and vascular delivery of cytotoxic therapy in a murine model of HER2+ breast cancer: preliminary results

To employ in vivo imaging and histological techniques to identify and quantify vascular changes early in the course of treatment with trastuzumab in a murine model of HER2+ breast cancer. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) was used to quantitatively characterize vessel perfusion/permeability (via the parameter K (trans) ) and the extravascular extracellular volume fraction (v e ) in the BT474 mouse model of HER2+ breast cancer (N = 20) at baseline, day one, and day four following trastuzumab treatment (10 mg/kg). Additional cohorts of mice were used to quantify proliferation (Ki67), microvessel density (CD31), pericyte coverage (α-SMA) by immunohistochemistry (N = 44), and to quantify human VEGF-A expression (N = 29) throughout the course of therapy. Longitudinal assessment of combination doxorubicin ± trastuzumab (N = 42) tested the hypothesis that prior treatment with trastuzumab will increase the efficacy of subsequent doxorubicin therapy. Compared to control tumors, trastuzumab-treated tumors exhibited a significant increase in K (trans) (P = 0.035) on day four, indicating increased perfusion and/or vessel permeability and a simultaneous significant increase in v e (P = 0.01), indicating increased cell death. Immunohistochemical and ELISA analyses revealed that by day four the trastuzumab-treated tumors had a significant increase in vessel maturation index (i.e., the ratio of α-SMA to CD31 staining) compared to controls (P < 0.001) and a significant decrease in VEGF-A (P = 0.03). Additionally, trastuzumab dosing prior to doxorubicin improved the overall effectiveness of the therapies (P < 0.001). This study identifies and validates improved perfusion characteristics following trastuzumab therapy, resulting in an improvement in trastuzumab-doxorubicin combination therapy in a murine model of HER2+ breast cancer. This data suggests properties of vessel maturation. In particular, the use of DCE-MRI, a clinically available imaging method, following treatment with trastuzumab may provide an opportunity to optimize the scheduling and improve delivery of subsequent cytotoxic therapy.

Techniques and applications of dynamic contrast enhanced magnetic resonance imaging in cancer

We first discuss several key technical issues associated with quantitative dynamic contrast enhanced magnetic resonance imaging (DCE-MRI), and then provide examples of DCE-MRI in oncology. In particular, we examine the importance of both active and passive delivery of the contrast agent to the tissue under investigation, and repeatability/reproducibility in DCE-MRI studies. We then discuss examples of how DCE-MRI can assist in assessing and predicting therapeutic response in the neoadjuvant setting.

Correlation of tumor characteristics derived from DCE-MRI and DW-MRI with histology in murine models of breast cancer

The purpose of this work was to determine the relationship between the apparent diffusion coefficient (ADC, from diffusion-weighted (DW) MRI), the extravascular, extracellular volume fraction (ve , from dynamic contrast-enhanced (DCE) MRI), and histological measurement of the extracellular space fraction. Athymic nude mice were injected with either human epidermal growth factor receptor 2 positive (HER2+) BT474 (n = 15) or triple negative MDA-MB-231 (n = 20) breast cancer cells, treated with either Herceptin (n = 8), Abraxane (low dose n = 7, high dose n = 6), or saline (n = 7 for each cell line), and imaged using DW- and DCE-MRI before, during, and after treatment. After the final imaging acquisition, the tissue was resected and evaluated by histological analysis. H&E-stained central slices were scanned using a digital brightfield microscope and evaluated with thresholding techniques to calculate the extracellular space. For both BT474 and MDA-MB-231, the median ADC of the central slice exhibited a significantly positive correlation with the corresponding central slice extracellular space as measured by H&E (p = 0.03, p < 0.01, respectively). Median ve calculated from the central slice showed differing results between the two cell lines. For BT474, a significant correlation between ve and extracellular space was calculated (p = 0.02), while MDA-MB-231 tumors did not demonstrate a significant correlation (p = 0.64). Additionally, there was no correlation discovered between ADC and ve with either whole tumor analysis or central slice analysis (p > 0.05). While ADC correlates well with the histologically determined fraction of extracellular space, these data add to the growing body of literature that suggests that ve derived from DCE-MRI is not a reliable biomarker of extracellular space for a range of physiological conditions.

Abstract 1492: Trastuzumab-induced normalization in a HER2+ murine model of breast cancer

Introduction: The primary goal of this study is to quantitatively map the vascular and cellular response to trastuzumab treatment in a murine model of HER2+ breast cancer. We report longitudinal dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) and immunohistochemical studies hypothesized to identify timing windows of trastuzumab-induced vascular normalization.

Experimental Design: Mice were subcutaneously implanted with BT474 breast cancer cells and randomly assigned to treated (10 mg/kg trastuzumab) and control (saline) groups. After tumors reached ∼225 mm3, animals (n = 20) were imaged (7.0 T MRI) before treatment (day 0), and 24 hours after each treatment (day 1 and day 4). Subgroups were sacrificed for histology between days 0 through 10 (n = 45). DCE-MRI analysis yielded parametric maps of blood vessel perfusion and permeability (Ktrans) and the extravascular extracellular volume fraction (ve). Tumor sections were paraffin-embedded and stained with CD31, α-SMA, Ki67 and H&E. Slides were scanned in high resolution (20×) and quantitatively analyzed with Leica SCN400 software.

Results: Compared to controls, treated tumors exhibited a significant increase in Ktrans (p = 0.03) on day 4, indicative of enhanced vessel perfusion and/or permeability. Additionally at day 4, treated tumors exhibited a significant increase in extravascular extracellular volume fraction measured via ve (p = 0.01), indicating increased cell death. These significant changes occurred prior to a significant change in tumor size at day 4 (p = 0.11). Decreased Ki67 proliferation staining (p = 0.02) at day 3 and a significant decrease in tumor volume at day 7 (p = 0.04) in the treated group confirmed tumor response to trastuzumab. The increase in Ktrans suggests properties of vessel normalization with potential to improve delivery of systemic therapies. Immunohistochemical analyses showed treated tumors have a significant decrease in microvessel density (CD31 staining, p &lt; 0.01), with a simultaneous significant increase in α-SMA staining (pericyte coverage, p = 0.05) on day 4; thus, there was an overall increase in the “vessel maturation index” (ratio of α-SMA to CD31 staining) compared to controls (p = 0.01).

Conclusion: These concordant (though preliminary) imaging and histological data suggest that trastuzumab treatment promotes vascular normalization, providing motivation for future studies designed to improve the efficacy of combination therapies in HER2+ breast cancer. For example, DCE-MRI has the potential to identify windows of vascular normalization thereby indicating optimal timing for treatment dosing with a cytotoxic therapy. As trastuzumab is currently given clinically in combination with various chemotherapies for HER2+ cancer, trastuzumab-induced vascular normalization could be utilized to improve drug delivery efficiency and enhance overall patient response without increasing dose or systemic toxicity.

Citation Format: Anna G. Sorace, Jennifer G. Whisenant, J. Oliver McIntyre, Thomas E. Yankeelov. Trastuzumab-induced normalization in a HER2+ murine model of breast cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1492. doi:10.1158/1538-7445.AM2015-1492

Evaluating treatment response using DW-MRI and DCE-MRI in trastuzumab responsive and resistant HER2-overexpressing human breast cancer xenografts

We report longitudinal diffusion-weighted magnetic resonance imaging (DW-MRI) and dynamic contrast enhanced (DCE)-MRI (7 T) studies designed to identify functional changes, prior to volume changes, in trastuzumab-sensitive and resistant HER2 + breast cancer xenografts. Athymic mice (N = 33) were subcutaneously implanted with trastuzumab-sensitive (BT474) or trastuzumab-resistant (HR6) breast cancer cells. Tumor-bearing animals were distributed into four groups: BT474 treated and control, HR6 treated and control. DW- and DCE-MRI were conducted at baseline, day 1, and day 4; trastuzumab (10 mg/kg) or saline was administered at baseline and day 3. Animals were sacrificed on day 4 and tumors resected for histology. Voxel-based DW- and DCE-MRI analyses were performed to generate parametric maps of ADC, K^trans, and v_e. On day 1, no differences in tumor size were observed between any of the groups. On day 4, significant differences in tumor size were observed between treated vs. control BT474, treated BT474 vs. treated HR6, and treated vs. control HR6 (P < .0001). On day 1, v_e was significantly higher in the BT474 treated group compared to BT474 control (P = .002) and HR6 treated (P = .004). On day 4, v_e and K^trans were significantly higher in the treated BT474 tumors compared to BT474 controls (P = .0007, P = .02, respectively). A significant decrease in Ki67 staining reinforced response in the BT474 treated group compared to BT474 controls (P = .02). This work demonstrated that quantitative MRI biomarkers have the sensitivity to differentiate treatment response in HER2 + tumors prior to changes in tumor size.

Sequence design and evaluation of the reproducibility of water-selective diffusion-weighted imaging of the breast at 3 T

Diffusion measurements derived from breast MRI can be adversely affected by unwanted signals from abundant fatty tissues if they are not suppressed adequately. To minimize this undesired contribution, we designed and optimized a water-selective diffusion-weighted imaging (DWI) sequence, which relies on spectrally selective excitation on the water resonance, obviating the need for fat suppression. As this method is more complex than standard DWI methods, we also report a test-retest study to evaluate its reproducibility. In this study, a spectrally selective Gaussian pulse on water resonance was combined with a pair of slice-selective adiabatic refocusing pulses for water-only DWI. Field map-based shimming and manual determination of the center frequency were used for water selection. The selectivity of the excitation pulse was optimized by a spectrally selective spectroscopy sequence based on the same principles. A test-retest study of 10 volunteers in two separate visits was used to evaluate its reproducibility. Our results from all subjects showed high-quality diffusion-weighted images of the breast without fat contamination. Mean apparent diffusion coefficients for b = 0, 600 s/mm(2) and b = 50, 600 s/mm(2) all showed good reproducibility, as 95% confidence intervals of the apparent diffusion coefficients were 4 × 10(-5)  mm(2) /s and 5 × 10(-5)  mm(2) /s and repeatability values were 1.09 × 10(-4) and 1.31 × 10(-4) , respectively. In conclusion, water-selective DWI is a feasible alternative to standard methods of DWI based on fat suppression. The added complexity of the method does not compromise the reproducibility of diffusion measurements in the breast.

Assessing reproducibility of diffusion-weighted magnetic resonance imaging studies in a murine model of HER2+ breast cancer

BACKGROUND AND PURPOSE

The use of diffusion-weighted magnetic resonance imaging (DW-MRI) as a surrogate biomarker of response in preclinical studies is increasing. However, before a biomarker can be reliably employed to assess treatment response, the reproducibility of the technique must be established. There is a paucity of literature that quantifies the reproducibility of DW-MRI in preclinical studies; thus, the purpose of this study was to investigate DW-MRI reproducibility in a murine model of HER2+ breast cancer.

MATERIALS AND METHODS

Test-Retest DW-MRI scans separated by approximately six hours were acquired from eleven athymic female mice with HER2+ xenografts using a pulsed gradient spin echo diffusion-weighted sequence with three b values [150, 500, and 800s/mm(2)]. Reproducibility was assessed for the mean apparent diffusion coefficient (ADC) from tumor and muscle tissue regions.

RESULTS

The threshold to reflect a change in tumor physiology in a cohort of mice is defined by the 95% confidence interval (CI), which was±0.0972×10(-3)mm(2)/s (±11.8%) for mean tumor ADC. The repeatability coefficient defines this threshold for an individual mouse, which was±0.273×10(-3)mm(2)/s. The 95% CI and repeatability coefficient for mean ADC of muscle tissue were±0.0949×10(-3)mm(2)/s (±8.30%) and±0.266×10(-3)mm(2)/s, respectively.

CONCLUSIONS

Mean ADC of tumors is reproducible and appropriate for detecting treatment-induced changes on both an individual and mouse cohort basis.

Reproducibility of static and dynamic (18)F-FDG, (18)F-FLT, and (18)F-FMISO MicroPET studies in a murine model of HER2+ breast cancer

PURPOSE

The objective of this study is to determine the reproducibility of static 2-deoxy-2-[(18)F]fluoro-D-glucose ((18)F-FDG), 3'-deoxy-3'-[(18)F]fluorothymidine ((18)F-FLT), and [(18)F]-fluoromisonidazole ((18)F-FMISO) microPET measurements, as well as kinetic parameters returned from analyses of dynamic (18)F-FLT and (18)F-FMISO data.

PROCEDURES

HER2+ xenografts were established in nude mice. Dynamic data were acquired for 60 min, followed by a repeat injection and second scan 6 h later. Reproducibility was assessed for the percent-injected dose per gram (%ID/g) for each radiotracer, and with kinetic parameters (K (1) -k (4) , K ( i )) for (18)F-FLT and (18)F-FMISO.

RESULTS

The value needed to reflect a change in tumor physiology is given by the 95 % confidence interval (CI), which is ±14, ±5, and ±6 % for (18)F-FDG (n = 12), (18)F-FLT (n = 11), and (18)F-FMISO (n = 11) %ID/g, respectively. V ( d ) (=K (1) /k (2)), k (3), and K (FLT) are the most reproducible (18)F-FLT (n = 9) kinetic parameters, with 95 % CIs of ±18, ±10, and ±18 %, respectively. V ( d ) and K (FMISO) are the most reproducible (18)F-FMISO kinetic parameters (n = 7) with 95 % CIs of ±16 and ±14 %, respectively.

CONCLUSIONS

Percent-injected dose per gram measurements are reproducible and appropriate for detecting treatment-induced changes. Kinetic parameters have larger threshold values, but are potentially sufficiently reproducible to detect treatment response.